MCM32257B

The MCM32257B is an 8M bit static random access memory module organized as 262,144 words of 32 bits. The module is a 64lead zigzag inline package (ZIP) of eight MCM6229 fast static RAMs packaged in 28lead SOJ
packages and mounted on a printed circuit board along with eight decoupling capacitors.

The MCM6229 is a highperformance CMOS fast static RAM organized as 262,144 words of 4 bits, fabricated using highperformance silicongate CMOS technology. Static design eliminates the need for external clocks or timing
strobes, while CMOS circuitry reduces power consumption and provides for greater reliability.

The MCM32257B is equipped with output enable (G) and four separate byte enable (E1 E4) inputs, allowing for greater system flexibility. The G input, when high, will force the outputs to high impedance. Ex high will do the same for byte x.

PD0 and PD1 are reserved for density identification. PD0 and PD1 are connected to ground. These pins can be used to identify the density of the memory module.
• Single 5 V ± 10% Power Supply
• Fast Access Time: 15/20/25 ns
• ThreeState Outputs
• Fully TTL Compatible
• JEDEC Standard Pinout
• Power Requirement: 960/880/840 mA Maximum, Active AC
• High Board Density ZIP Package
• Byte Operation: Four Separate Chip Enables, One for Each Byte (Eight Bits)
• High Quality FourLayer FR4 PWB with Separate Internal Power and Ground Planes
• Incorporates Motorola's StateoftheArt Fast Static RAMs